Abstract: According to one embodiment, a beam splitter splits light into first light and second light. The second light is used to irradiate a sample containing particles. A first imaging device images a first interference pattern formed by multiplexing third light, which has been generated by irradiating the particles with the second light, and the first light. A second imaging device images a second interference pattern formed by the third light. An arithmetic device compares a composite image with a calculated image. The composite image is created by using a first interference image picked up by the first imaging device and a second interference image picked up by the second imaging device. The calculated image is obtained by combining single particle interference images, each of which is expected to be obtained by the first imaging device in a case where a particle is present alone in the sample.

Abstract: According to one embodiment, a beam splitter splits light into first light and second light. The second light is used to irradiate a sample containing particles. A first imaging device images a first interference pattern formed by multiplexing third light, which has been generated by irradiating the particles with the second light, and the first light. A second imaging device images a second interference pattern formed by the third light. An arithmetic device compares a composite image with a calculated image. The composite image is created by using a first interference image picked up by the first imaging device and a second interference image picked up by the second imaging device. The calculated image is obtained by combining single particle interference images, each of which is expected to be obtained by the first imaging device in a case where a particle is present alone in the sample.

Abstract: According to one embodiment, an information recording and reproducing apparatus including, a focus control module, an objective lens control module, a calculation module, and a tracking control module. If, detection the recording marks line, to focus a laser light of a second wavelength to the recording layer through an objective lens and to operation a recording layer tracking control using a tracking error signal taken out from a second reflected light and a laser light of a first wavelength to a track groove through the objective lens and to operation a guide layer tracking control to control the objective lens using a tracking error signal taken out from a first reflected light.

Abstract: According to one embodiment, a pickup head includes a plurality of light sources, a first objective lens, second objective lens, a driving unit, a first control unit, a second control unit, light receiving units. The first objective lens focuses a first light beam at a first recording layer. The second objective lens focuses a second light beam at a second recording layer. The driving unit moves the first objective lens and the second objective lens in a first direction and a second direction. The first control unit corrects displacement from target track along the first direction. The second control unit controls a moving direction of a position of the second light spot in the second direction.

Abstract: According to one embodiment, an optical pickup configured to record and to reproduce on a layer of a disk, including, a light source configured to emit a laser beam, an objective lens including a variable use magnification and configured to focus the laser beam on the layer, a collimator lens configured to change the magnification of the objective lens by moving along an optical axis direction, and a liquid crystal module configured to generate spherical aberration to cancel a coma aberration which may occur because an object point and an image point of the objective lens at the use magnification do not exist on an optical axis of the objective lens.

Abstract: A focus servo control device includes a first detector, first controller, second detector, and second controller. The first detector detects a first focus error signal. The first controller controls the objective lens based on the first focus error signal, so that a focal point of the first laser agrees with the guide layer. The second detector detects a second focus error signal. The second controller changes a relative distance between the focal point of the second laser and the focal point of the first laser, so that the focal point of the second laser agrees with a target recording/reproducing layer.

Abstract: According to one embodiment, an optical pickup configured to record and to reproduce on a layer of a disk, including, a light source configured to emit a laser beam, an objective lens including a variable use magnification and configured to focus the laser beam on the layer, a collimator lens configured to change the magnification of the objective lens by moving along an optical axis direction, and a liquid crystal module configured to generate spherical aberration to cancel a coma aberration which may occur because an object point and an image point of the objective lens at the use magnification do not exist on an optical axis of the objective lens.

Abstract: According to one embodiment, an information recording medium characterized by including, a first servo layer, a second servo layer, and a data layer, the information recording medium further including, a first spiral track and a second spiral track formed between the first servo layer and the second servo layer and spiraling in opposite directions.

Abstract: According to one embodiment, an information recording and reproducing apparatus including, a focus control module, an objective lens control module, a calculation module, and a tracking control module. If, detection the recording marks line, to focus a laser light of a second wavelength to the recording layer through an objective lens and to operation a recording layer tracking control using a tracking error signal taken out from a second reflected light and a laser light of a first wavelength to a track groove through the objective lens and to operation a guide layer tracking control to control the objective lens using a tracking error signal taken out from a first reflected light.

Abstract: A focus servo control device includes a first detector, first controller, second detector, and second controller. The first detector detects a first focus error signal. The first controller controls the objective lens based on the first focus error signal, so that a focal point of the first laser agrees with the guide layer. The second detector detects a second focus error signal. The second controller changes a relative distance between the focal point of the second laser and the focal point of the first laser, so that the focal point of the second laser agrees with a target recording/reproducing layer.

Abstract: According to one embodiment, a pickup head includes a plurality of light sources, a first objective lens, second objective lens, a driving unit, a first control unit, a second control unit, light receiving units. The first objective lens focuses a first light beam at a first recording layer. The second objective lens focuses a second light beam at a second recording layer. The driving unit moves the first objective lens and the second objective lens in a first direction and a second direction. The first control unit corrects displacement from target track along the first direction. The second control unit controls a moving direction of a position of the second light spot in the second direction.

Abstract: An optical information reproducing method includes: obtaining information about a wavelength of a reference beam at recording time from a recording medium which stores main information recorded as a pattern corresponding to interference between an information beam and the reference beam and information about the wavelength of the reference beam at the recording time; determining an aiming temperature, which is a temperature of the recording medium suited to reproduce the pattern; determining an aiming incident angle, which is an incident angle of the reference beam at the reproducing time suited to reproduce the pattern; controlling the temperature of the recording medium so that the temperature of the recording medium is generally equal to the aiming temperature; and controlling the incident angle of the reference beam at the reproducing time so that the incident angle of the reference beam at the reproducing time is generally equal to the aiming incident angle.

Abstract: An apparatus includes: a light source; a splitting unit that splits a light beam into an information beam and a reference beam; a spatial light modulator that modulates the information beam into a grating binary pattern having bright points and dark points; an irradiation unit that irradiates the reference beam and the information beam onto a hologram recording medium to record information corresponding to each of the regions of the spatial light modulator; a photodetector that detects a signal beam that is diffracted from the hologram recording medium by irradiating the hologram recording medium with a reproduction beam emitted by the light source; and a power detector that detects a difference of powers of signal beams detected by the photodetector at portions in the hologram recording medium corresponding to two of the regions of the spatial light modulator.

Abstract: An exemplary optical pick-up apparatus of the invention includes: a first light source configured to emit a light beam of a first wavelength; a second light source configured to emit a light beam of a second wavelength, the second wavelength longer than the first wavelength; a third light source configured to emit a light beam of a third wavelength, the third wavelength longer than the second wavelength, wherein the first, second, and third light sources emit light beams one at a time during a reading or writing operation; a first dichroic element configured to transmit the light beam of the first wavelength and to reflect the light beam of the second wavelength; a second dichroic element configured to reflect the light beams of the first and second wavelengths and to transmit the light beam of the third wavelength; and an objective lens configured to transmit light beams of the first and second wavelengths, that have interacted with the first and second dichroic elements, to transmit the third wavelength, th